The present invention relates to a method of subdividing a web into discrete sections, particularly subdividing a web of paper, cardboard or other wrapping material into discrete blanks which can be converted into constituents of containers for arrays of cigarettes, cigars, cigarillos or analogous rod-shaped articles of the tobacco processing industry. Still more particularly, the invention relates to improvements in a method of making blanks which can be converted into constituents of so-called soft packs for arrays of cigarettes or analogous rod-shaped articles (hereinafter called cigarettes for short).
Soft packs which are produced in cigarette packing machines are normally assembled of several blanks, e.g., a blank consisting of metallic foil, at least one blank consisting of paper or cardboard, and a blank made of transparent or translucent material. Such blanks can be prefabricated and stored in a magazine which is installed in or adjacent to the packing machine, and the machine then further comprises a suitable mechanism which transfers blanks from the magazine to the location where the blanks are converted into inner envelopes, outer envelopes or other constituents of cigarette packs. Alternatively, the blanks are obtained by subdividing a web of wrapping material into sections by severing the web across its leader so that the yields a succession of discrete sections or blanks which are ready for conversion into constituents of packs. The web is drawn from a reel or another suitable source of supply and can be subdivided into a succession of blanks in a manner as disclosed in the aforementioned commonly owned copending application Ser. No. 315,434 of Steinhauer et al. The supply of web on the core of the reel is provided with printed matter and other informative or decorative material, and the severing action of the apparatus is such that each of the blanks contains the same information or decorative material. The present invention relates to a method and apparatus for obtaining blanks or like web sections by repeatedly severing a web directly in or adjacent to a packing machine for cigarettes or the like.
As disclosed in the aforementioned copending application Ser. No. 315,434, the web is preferably advanced in stepwise fashion and is severed during the intervals of dwell between successive stepwise movements in a predetermined direction. Successive sections or blanks are thereupon engaged by suitable blank transferring instrumentalities for introduction into the packing machine proper, e.g., to a station where the blanks are draped around hollow mandrels containing arrays of cigarettes in predetermined formations, normally arrays containing two outer layers of seven cigarettes each and a median layer containing six cigarettes which are staggered sideways with reference to the cigarettes of the outer layers.
If the seam where the marginal portions of a converted blank overlap each other is to be adjacent to an edge flanking a major side of the converted blank, both marginal portions of the blank are normally provided triangular cutouts or notches. It would suffice to provide such notches only in one marginal portion of the web which is being converted into discrete blanks, namely, one notch for each of the blanks, so that a blank which has been separated from the remainder of the blank is devoid of one corner. However, for convenience of manufacture, the web is normally formed with two rows of triangular notches, one row in each of the two marginal portions. The web is further provided (or can be provided) with a row of indicia which are monitored by a suitable scanner to ensure that the web is severed at predetermined intervals and in such a way that each cut is made between two transversely aligned triangular cutouts. This guarantees that each blank is devoid of two of its corners (due to the presence of transversely aligned triangular notches in the respective portions of the web). The cutting operation must be carried out with a high degree of precision, not only as regards the making of notches and the alignment of notches in one marginal portion with the notches in the other marginal portion of the web but also as concerns the position of the cutting plane with reference to the nearest notches. In the absence of adherence to such high degree of accuracy, the appearance of the blanks and of the envelopes which are obtained therefrom would be unsightly and therefore unacceptable to the manufacturer as well as to the purchaser of cigarette packs. Adherence to very high degrees of accuracy in connection with the application of indicia to the web, in connection with the making of notches in the marginal portions of the web, in connection with the scanning and advancing of the web, as well as in connection with cutting in a plane which is optimally positioned with reference to the neighboring notches, presents serious problems in many high-speed packing machines which turn out several hundreds of cigarette packs per minute.